Mounting assembly for a shaft of a power tool

ABSTRACT

A mounting assembly for an intermediate shaft of a power tool having a clam-shell housing with a support portion and a cover portion. The support portion has a hollow interior in which is formed support means for carrying a shaft of the gear train. A gear is journaled on the shaft and disposed between a retainer, which engages the shaft adjacent the support means. Assembly of the cover portion causes the retainer to be urged toward the shaft to lock the shaft in assembled non-rotative position.

United States Patent Seely et al.

[ June 25, 1974 [5 MOUNTING ASSEMBLY FOR A SHAFT 0F A POWER TOOL Primary Examiner-Leonard H. Gerin [76] Inventors: Robert W. Seely, Easley; David J. Attorney Agent or Firm-Marsha" Bree" Nalley, Liberty, both of S.C. {57] ABSTRACT [22] Filed: July 18, 1973 A mounting assembly for an intermediate shaft of a [21] Appl. No.1 380. power tool having a clam-shell housing with a support portion and a cover portion. The support portion has [52] US. Cl 74/421 A a hollow interior in which is formed Support means for 51 Int. Cl. F16h 1/20 Carrying a shaft F gear A gear i [58] Field of Search 74/421 A the Shaft and maimed a mam", whlch engages the shaft adjacent the support means. Assem- [56] References Cited bly oiftthe 302/51 ioigionlcazsfz th: trtetainer toblbg urge owar es a 0 oc es a massem e 2 392 097 r vi PATENTS 7 M I A non-rotative position.

eunier 4 2 3,651,707 3/1972 Rees 74/421 A 1 Claims, 6 Drawing gu "I 26, J, L I O l l l I ;--i1-"4 -w ,L L ,'J I! I o o I I 1 1 o 1111:. t 24 4o i 54 36 2 u2|oo2 2 3 MOUNTING ASSEMBLY FOR A SHAFT OF A POWER TOOL BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved mounting assembly for a shaft which overcomes the prior art disadvantages; which is simple, economical and reliable; which uses a retainer clamped in position by the cover portion of the housing to lock the shaft in assembled position; which uses a retainer to separate the gear journaled on the shaft from the housing; which uses a retainer to assemble an intermediate shaft of a drive train; which uses a retainer which permits the passage of a pinion gear through to drive the gear carried by the shaft held by the retainer; which uses a substantially U-shaped retainer; which uses a resiliently mounted retainer; and which has a gear journalled on a non-rotative shaft held in place by a retainer.

Other objects and advantages will be apparent by the following description of one embodiment of the invention and the novel features will be particularly pointed hereinafter in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS This invention is illustrated in the accompanying drawings in which:

FIG. 1 is a side elevational view, partly in section, of a power tool such as a portable drill embodying the present invention.

FIG. 2 is a sectional bottom plan view taken along line 2-2 of FIG. 1.

FIG. 3 is a sectional side view taken along line 3--3 of FIG. 2 with the power tool on its side. 7

FIG. 4 is a sectional side view taken along line 4-4 of FIG. 2 with the power tool reversed.

FIG. 5 is a sectional bottom plan taken along line 55 of FIG. 3.

FIG. 6 is a perspective view of the retainer used in the present invention.

DESCRIPTION OF THE INVENTION A powertool, such as a portable power drill 20, is shown in FIG[] embodying the present invention. The drill includes an electric motor 22 having an armature shaft 24 which carries a commutator 26, engaged by a brush assembly 28. The armature shaft 24 is journaled in a pair of spaced bearings 30, and has a drive pinion 32 formed at its outer end. The motor 22 is mounted in a housing 34 which, in the preferred embodiment illustrated in FIG. 1, has a support portion 36 and a cover portion 38 suitably connected to each-other as by screw means 40 so as to form what it commonly termed a clam-shell housing. The housing 34 has an integrally formed pistol grip handle 42 which receives an electric cord 44 that in turn is connected through a trigger switch 46 to the motor 22 in the usual manner. A gear chamber 48 is formed in the front portion of the housing and has a gear train 50 mounted therein to transmit the rotational movement from the motor 22 to a chuck 52 which is adapted to drive a suitable bit or implement that comes into engagement with the work.

The gear train 50 is illustrated in FIGS. 2 through 5, and serves the conventional functions of (l) reducing the relative high rotational speed of the drive pinion 32, and (2) increasing the torque delivered to the chuck 52. The gear train 50 includes the pinion 32 which engages the larger gear 54 of a cluster gear 56, the smaller gear 58 of which engages a spindle gear 60. The cluster gear 56 is rotatively mounted on a non-rotative shaft 62, while the spindle gear 60 is fixedly connected to a spindle 64, the projecting end of which carries the chuck 52.

The gear chamber 48 is formed in the front portion of the housing 34 by the mating of the support portion 36 and the cover portion 38 thereof. The support portion 36 and the cover portion 38 have aligned front walls 66 and 68, respectively, and aligned rear walls 70 and 72, respectively, which are bounded by a support side 74 and a cover side 76. The support portion 36 has a front support rib 78 extending parallel to and formed integrally with the front wall 66. Also, a rear support rib 80 extends parallel to and formed integrally with the rear wall 70. The ribs 78 and 80 extend from one end of the side 74 as illustrated in FIG. 4 to terminate in a front support boss 82 and a rear support boss 84, respectively. The front support boss is formed integrally with and extends between the front wall 66 and the side 74, while the rear support boss 84 is formed integrally with and extends between the rear wall 70 and the side 74. The bosses 82 and 84 extend from one edge of the side 74 in the direction of the cover portion 38, as is seen in FIG. 5 terminate about halfway from the edge to a joinder split 86. The outer surfaces of the bosses 82 and 84, remote from the side 74 have aligned recesses 88 and 90, respectively, with the rear recess 90 having a shoulder 92 to define a step therein. The shaft 62 has its outer ends disposed within the recesses 88 and 90, and has a slabbed cut-out 94 formed at one end to be disposed upon the shoulder 92 whereby the shaft 62 will be rendered non-rotative. The cluster gear 56 is journaled to the shaft 62 by a pair of sleeve bearings 96 rotatably carried on the shaft 62 a short axially distance from each other.

A retainer 100 is illustrated best in FIG. 6 as having a substantially U-shape with'a pair of parallel legs 102 and 104 which are joined by an arcuate base portion 106. A shaft slot 108 is formed at the outer end of the legs 102 and 104. An aperture 110 is formed on the leg 102 intermediate the base 106 and the slot 108. Theretainer 100 is illustrated in assembled position in FIGS. 2 through 5 wherein after the shaft 62 has been placed within the recesses 88 and 90 the slots will straddle the shaft 62 while the base portion 106 abuts the side 76 of the cover 38 through a cushion pad 112 to urge the shaft to remain in assembled position within the recesses 88 and 90.

The cluster gear 56 is disposed within the retainer 100, with the pinion 32 extending through the aperture 110 of the leg 102 to operative engage the larger gear 54 to rotate the same. This causes rotation of the smaller gear 58 which is in contact with the spindle gear 60 of the gear train 50 as described hereinbefore.

ln the preferred embodiment the retainer 100 will be made of metal. The retainer 100 acts to prevent the cluster gear 56 from sliding along the shaft 62 so as to keep it out of contact with the front and rear support bosses 82 and 84 which are preferably made of plastic, as is the housing 34. The separation is obtained by physically placing the legs 102 and 104, respectively, between the front and rear support bosses 82 and 84. This permits proper ventilation of the reduction gear and prevents over-heating of the plastic housing 34 which might otherwise result if the gear had been affixed to a rotative shaft journaled in the plastic housing 34. Thus, the retainer 100 also acts as a heat sink, while the use of a non-rotative shaft 62 lessens the problem of excessive heat build-up within the plastic housing 34.

In assembling the drill 20 the cover portion 38 is removed from the support portion 36 of the housing 34 to permit the motor 22 and the gear 50 to be assembled therein. The shaft 62 will have the cluster gear 56 mounted thereon and disposed within the recesses 88 and 90 either before or after the assembly of the motor 22 and the remainder of the gear train 50. The retainer will be placed upon the shaft 62 so that the outer ends of the legs 102 and 104 straddle the shaft 62 about the slots 108 with the pinion 32 extending through the aperture 110. The pad 112 may be placed against or affixed to the base portion 106 or the interior of the side 76 as desired. Upon assembling the cover portion 38 to the support portion 36, the pad 112 will be slightly compressed to lightly pressure the retainer 100 in the direction of the shaft 62 and hold the same in that position to prevent outward movement of the shaft 62 seated within the recesses 88 and 90. The shaft 62 is also prevented from rotating by the slabbed cut-out 94 seated upon the shoulder 92. Though the use of a retainer 100 is not limited to a clam-shell type housing 34 it is especially suitable for use with the plastic type clam-shell housing 34 as it aids in ease of assembly and eliminates possible problems of excessive heat build-up in the plastic support housing which might otherwise occur with the use of conventional construction.

It will be understood that various changes in the details, materials, arrangements of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principles and scope of the invention.

Having thus set forth the nature of the invention, what is claimed herein is:

l. A mounting assembly for a shaft of a power tool comprising:

a. a housing for the power tool having a support portion and a cover portion,

b. the support portion having a hollow interior,

c. a support means formed in the support portion,

(1. a shaft carried upon the support means,

e. a gear journaled on the shaft,

f. a retainer engaging the shaft adjacent the support means, and

g. the cover portion to contact the retainer and urge the retainer in the direction of the shaft to lock the shaft in assembled position.

2. The combination claimed in claim 1 wherein:

a. the support means includes two spaced support members,

b. a recess is formed in each of the support members,

c. the ends of the shaft are disposed into the recesses,

and

d. the retainer engages each end of the shaft adjacent the recess.

3. The combination claimed in claim 2 wherein:

a. the retainer is substantially U-shaped with an open end bounded by two legs and a closed end connecting into the legs,

b. the open end of the retainer faces the shaft,

0. the closed end of the retainer faces the cover portion, and

d. each of the legs engages the shaft adjacent one of the recesses.

4. The combination claimed in claim 3 wherein:

a. a resilient means is disposed between the closed end of the retainer and the cover portion to permit the retainer to be yieldably urged in the direction of the shaft.

5. The combination claimed in claim 1 wherein:

a. the support portion of the housing is made of a plastic material,

b. the gear extends within the retainer and is separated from the support members by the legs of the retainer.

6. The combination claimed in claim 1 wherein:

a. the shaft is non-rotatively connected to the support means,

b. the retainer is yieldably urged in the direction of the shaft.

7. The combination claimed in claim 6 wherein:

a. a gear train drives the power tool,

b. the gear is intermediate the gear train,

0. the gear is disposed within the retainer for connection with the gear train therein.

8. The combination claimed in claim 7 wherein:

a. the retainer is substantially U-shaped and has a pair of spaced legs engaging opposite ends of the shafts,

b. an aperture is formed in one of the legs,

c. a drive pinion extends through the aperture to drivingly engage the gear.

9. The combination claimed in claim 1 wherein:

a. a bearing journals'the gear to the shaft.

10. The combination claimed in claim 9 wherein:

a. the bearing defines a pair of space sleeve bearings. 

1. A mounting assembly for a shaft of a power tool comprising: a. a housing for the power tool having a support portion and a cover portion, b. the support portion having a hollow interior, c. a support means formed in the support portion, d. a shaft carried upon the support means, e. a gear journaled on the shaft, f. a retainer engaging the shaft adjacent the support means, and g. the cover portion to contact the retainer and urge the retainer in the direction of the shaft to lock the shaft in assembled position.
 2. The combination claimed in claim 1 wherein: a. the support means includes two spaced support members, b. a recess is formed in each of the support members, c. the ends of the shaft are disposed into the recesses, and d. the retainer engages each end of the shaft adjacent the recess.
 3. The combination claimed in claim 2 wherein: a. the retainer is substantially U-shaped with an open end bounded by two legs and a closed end connecting into the legs, b. the open end of the retainer faces the shaft, c. the closed end of the retainer faces the cover portion, and d. each of the legs engages the shaft adjacent one of the recesses.
 4. The combination claimed in claim 3 wherein: a. a resilient means is disposed between the closed end of the retainer and the cover portion to permit the retainer to be yieldably urged in the direction of the shaft.
 5. The combination claimed in claim 1 wherein: a. the support portion of the housing is made of a plastic material, b. the gear extends within the retainer and is separated from the support members by the legs of the retainer.
 6. The combination claimed in claim 1 wherein: a. the shaft is non-rotatively connected to the support means, b. the retainer is yieldably urged in the direction of the shaft.
 7. The combination claimed in claim 6 wherein: a. a gear train drives the power tool, b. the gear is intermediate the gear train, c. the gear is disposed wIthin the retainer for connection with the gear train therein.
 8. The combination claimed in claim 7 wherein: a. the retainer is substantially U-shaped and has a pair of spaced legs engaging opposite ends of the shafts, b. an aperture is formed in one of the legs, c. a drive pinion extends through the aperture to drivingly engage the gear.
 9. The combination claimed in claim 1 wherein: a. a bearing journals the gear to the shaft.
 10. The combination claimed in claim 9 wherein: a. the bearing defines a pair of space sleeve bearings. 